[motorheaddown]

There are a number of aftermarket pistons out there, but do they have an oil gallery cast into the top of the piston? That would seem almost impossible on a forged piston. If not, do aftermarkets compensate for the lack of an oil gallery by some other method to pull heat away from the combustion area?

Did a search on "piston and cooling" and "piston and aftermarket and cooling". Got a lot of hits but no answers to this question.

Thanks,
-scott

 

[RacingTechnology]

I think the trick lies in the Rod. Oil shoots up the rod from the journal and then into the pison. Also there are oil squirters that shoot oil onto the bottom of the piston as well. That would be the only way to get oil to the piston itself.

 

[97twinturbo]

The jet sprays the oil into an aluminum pipe that is cast right into the piston.

http://www.mkiv.com/specifications/ncf/ncf93/ncf083.jpg

 

[motorheaddown]

The jet sprays the oil into an aluminum pipe that is cast right into the piston.

http://www.mkiv.com/specifications/ncf/ncf93/ncf083.jpg

97twin,

I know the OEM pistons support oil cooling; I'm inquiring about aftermarket pistons. I would think it's difficult to cast or machine an oil gallery into an aftermarket piston... ergo the question.

-scott

 

[racing fan]

Scott,
I've never heard of an aftermarket piston that does.... hence my argument that the gte's oil cooling isn't going to allow anymore more power capacity than a 2jzge

 

[motorheaddown]

Scott,
I've never heard of an aftermarket piston that does.... hence my argument that the gte's oil cooling isn't going to allow anymore more power capacity than a 2jzge

I made that same argument on the mkiv mailing list and was told otherwise. You can't under estimate the ability to pull heat out of the piston due to oil cooling. However, I'm still interested in knowing whether or not an aftermarket piston has provisions for an oil gallery under the dish.

-scott

 

[97twinturbo]

97twin,

I know the OEM pistons support oil cooling; I'm inquiring about aftermarket pistons. I would think it's difficult to cast or machine an oil gallery into an aftermarket piston... ergo the question.

-scott

I should have quoted RacingTech. I was replying to him. I searched and didn't really come up with any info on aftermarket pistons supporting the oil jets. I would guess that some of the oil does make it's way to the underside of the pistons even without the gallery. I would imagine that you could also redirect the jet to spray oil directly on the underside of an aftermarket piston.